Light your candle for as long as it takes for the entire top layer of your candle to completely melt. You want a melt pool to be about a ¼ in depth around the jar.
This will do 2 things for you:
This will make your fragrance as strong as it will be for that candle
Every time your candle solidifies it will solidify evenly.
Trim your wicks!
Recommended height is ¼ of an inch (you can leave it slightly longer for the 1st light)
Trimming your wicks will significantly reduce soote.